ABSTRACT
Substation grounding design considerations are important to ensure the safety of personnel and the public, to minimize hazard from transferred potential, to protect equipment insulation, to provide a discharge path for lightning strikes, and to provide a low-resistance path to ground. The most accurate representation of a grounding system should be based on the actual variations of earth resistivity present at the substation site. Induced voltages on unshielded communication circuits, static wires, and pipes may result in transferred potentials exceeding the ground-potential rise of both the faulted substation and the source substation. The station fence grounding is of major importance because the outside of the fence is usually accessible to the general public, and the voltage involved is the more dangerous touch voltage. Isolating the station fence from the main grid introduces the possibility of inadvertent electric connection between the grid and the fence areas.
